% Copyright 2007 by Till Tantau
% Copyright 2015 by Vedran Mileti\'c, Joseph Wright
% Copyright 2019,2020,2022 by Joseph Wright, samcarter
%
% This file may be distributed and/or modified
%
% 1. under the LaTeX Project Public License and/or
% 2. under the GNU Public License.
%
% See the file LICENSE.md for more details.

\mode<presentation>

\useoutertheme{split}

\setbeamercolor{frametitle}{parent=subsection in head/foot}
\setbeamercolor{frametitle right}{parent=section in head/foot}

\pgfdeclarehorizontalshading[frametitle.bg,frametitle right.bg]{beamer@frametitleshade}{\paperheight}{%
  color(0pt)=(frametitle.bg);
  color(\paperwidth)=(frametitle right.bg)
}

\pgfdeclareverticalshading{beamer@topshade}{2\paperwidth}{%
  color(0pt)=(pgftransparent!100);
  color(8pt)=(pgftransparent!0)
}

\pgfdeclarefading{beamer@topshadowmask}{\pgfuseshading{beamer@topshade}}

\addtobeamertemplate{headline}
{}
{%
  \vskip0pt
  \begin{pgfpicture}
    \pgfpathrectangle{\pgfpoint{0pt}{-4pt}}{\pgfpoint{\paperwidth}{4pt}}%
    \pgfsetfading{beamer@topshadowmask}{}%
    \pgfusepath{fill}%
  \end{pgfpicture}
  \vskip-2pt
}

\defbeamertemplate*{frametitle}{shadow theme}
{%
  \nointerlineskip%
  \vskip-2pt%
  \hbox{\leavevmode
    \advance\beamer@leftmargin by -12bp%
    \advance\beamer@rightmargin by -12bp%
    \beamer@tempdim=\textwidth%
    \advance\beamer@tempdim by \beamer@leftmargin%
    \advance\beamer@tempdim by \beamer@rightmargin%
    \hskip-\Gm@lmargin\hbox{%
      \setbox\beamer@tempbox=\hbox{\begin{minipage}[b]{\paperwidth}%
          \vbox{}\vskip-.75ex%
          \leftskip0.3cm%
          \rightskip0.3cm plus1fil\leavevmode
          \usebeamercolor[fg]{frametitle}\usebeamerfont{frametitle}\strut\insertframetitle\strut\par%
          \ifx\insertframesubtitle\@empty\else%
            {\usebeamerfont*{framesubtitle}{\usebeamercolor[fg]{framesubtitle}\insertframesubtitle}\strut\par}%
          \fi%
          \nointerlineskip
          \vbox{}%
          \end{minipage}}%
      \beamer@tempdim=\ht\beamer@tempbox%
      \advance\beamer@tempdim by 2pt%
      \begin{pgfpicture}{0pt}{0pt}{\paperwidth}{\beamer@tempdim}
        \begin{pgfscope}
          \pgfsetfillcolor{beamer@safeblack}%
          \pgfpathrectangle{\pgfpoint{0pt}{-4pt}}{\pgfpoint{\paperwidth}{8pt}}%
          \pgfsetfading{beamer@topshadowmask}{}%
          \pgfusepath{fill}%
        \end{pgfscope}
        \begin{pgfscope}
          \usebeamercolor{frametitle right}%
          \pgfpathrectangle{\pgfpointorigin}{\pgfpoint{\paperwidth}{\beamer@tempdim}}%
          \pgfusepath{clip}%
          \pgftext[left,base]{\pgfuseshading{beamer@frametitleshade}}%
        \end{pgfscope}
      \end{pgfpicture}
      \hskip-\paperwidth%
      \box\beamer@tempbox%
    }%
    \hskip-\Gm@rmargin%
  }%
  \vskip-2pt
}

\mode
<all>
